Hydrophobic benefit agents (e.g., oils) can provide moisturizing and/or conditioning benefits to the skin or hair. At present, however, it is extremely difficult to achieve high levels of deposition from personal product compositions, particularly wash-off products, such as personal wash liquid and bar cleansers.
While this and co-pending applications are described with skin cleansing personal product language, to the extent the structured benefit agents can be used in a variety of other compositions where deposition of benefit agents is desirable (e.g., hair, deodorant), the claims are intended to be read expansively and limited only by the structuring component.
Unexpectedly, applicants have found that use of certain “structured” benefit agents (e.g., oils and other hydrophobic benefit agents) act as so-called delivery vehicles for the benefit agent(s) leading to multiple benefits relative to benefit agents which are delivered without the specific structuring of the invention; or relative to other benefit agents used in the final composition where no other structured benefit agents are used. According to the invention, preferably the benefit agent being structured and the structuring material (e.g., hydrogenated oil or fat) are separate components.
By specifically selecting particular crystalline structurant or structurants (i.e., so that the crystals have specifically defined aspect ratios), and by separately preparing structured benefit agent as a premix in the manner described (i.e., separate preparation and incorporation into product in molten, semi-molten or solid state), the benefit agent structurant vehicle (i.e., structured benefit agent vehicle) provides enhanced deposition as well as desired in-use and after-use sensory attributes (e.g., smooth skin feel).
As noted, such structured benefit agent also helps deposition of other benefit agents whether used in the same pre-mix (it is not clear whether they are separately structured or trapped in a network, but result is same), or whether separately added with other composition components.
Specifically, the invention relates to the use of hydrophobic benefit agent or agents structured by crystalline structurant or structurants selected from the group consisting of crystalline structuring materials (e.g. fats or hydrogenated oils) wherein, when the structured benefit vehicle is separately prepared before combining with the personal product composition, for example, the final composition is provided with enhanced benefit agent deposition to substrate. This enhanced deposition is dependent on the benefit agent, but can broadly be defined as at least 5% greater, preferably at least 10% greater and often far more than the level of deposition obtained if the benefit agent was added without being structured or without being in the presence of a structured benefit agent in the final formulation.
In one embodiment, benefit agents (i.e., benefit agent oils) are deposited from a personal product liquid cleanser composition, in an amount of greater than about 60 μg/cm2 (measured in accordance with protocol for measuring deposition from liquids described herein). In a second embodiment, benefit agents (i.e., benefit agent oils) deposited from a personal product bar composition, for example, provide the final composition with benefit agent deposition greater than about 5 μg/cm2 (according to protocol for measuring deposition from bars). Unlike prior art references where deposition is dependent on the large size of the benefit agent droplets (e.g., >50 micrometers average droplet diameter), the deposition results of the subject invention have no requirement of large droplet size. The structured benefit agent also provides enhanced deposition of hydrophobic or hydrophilic benefit agents separately added.
Among the crystalline materials which may be used are included hydrogenated oils or fats, fatty acids, fatty alcohols, salts of fatty acids, hydroxy fatty acids and fatty acid esters.
Some prior art references purport to use rheological parameters to select oils or oil blends to be used for improving deposition or providing favorable sensory feel. U.S. Pat. No. 5,674,511 to Kacher et al., for example, describes the use of solubility parameters and four rheological parameters to select benefit agents (i.e., oil or oil blends) that can be used in moisturizing cleansing formulations to improve deposition and provide favorable sensory feels. Petrolatum and petrolatum-containing mixtures are said to be favorable selections. The reference fails to teach or suggest the building of a deformable network of crystals within the benefit agent for which crystals must have a specific aspect ratio. The Kacher reference fails to teach or suggest that the structured benefit agent can be combined with other components in the compositions in a molten, semi-molten or solid state. Also, it does not describe separate benefit agent and structurant, as is preferred by the subject invention (i.e., in the subject invention, if petrolatum is used, it is used as a structurant to structure other benefit agents rather than itself comprise the structured benefit agent). In short, the benefit agents (e.g., oils) of Kacher clearly do not appear to be internally structured delivery vehicles like those used in the compositions of the invention which are separately prepared and wherein structurant has a defined aspect ratio.
A number of prior art references disclose generally the concept of an oil additive which can thicken or stabilize oils. They do not, however teach or disclose that specific crystalline structurant (i.e., having a defined aspect ratio), when prepared in combination with a hydrophobic benefit agent as a premix/delivery vehicle (added in a molten, semi-molten or solid state; and combined with a carrying composition), will enhance deposition (e.g., in an amount at least 5% greater than if no structured benefit agent is used at all and/or will provide enhanced sensory benefits). Moreover, in contrast to these references where deposition is disclosed as a function of large droplet size of the benefit agent, in the subject invention deposition will occur independent of such large droplet size requirement.
U.S. Pat. No. 5,804,540 to Tsaur et al. and U.S. Pat. No. 5,661,189 to Grieveson, for example, disclose use of both crystalline or micro-crystalline waxes and hydrophobic polymers to thicken low viscosity oil so as to control the oil droplet size (i.e., it must attain a certain minimum size to deposit) as well as to maintain high lather. As noted above, however, there is no discussion of the criticality of crystalline structure (aspect ratio) or that a thickened benefit agent must be separately prepared and added in a molten, semi-molten or solid state. Further, as noted, there is no recognition that it is critical the thickener must be a natural or synthetic crystalline structuring material (as is the case with subject invention) or that deposition occurs without the need for large droplet size. Indeed, the preferred thickening materials claimed in these patents provide only a very modest enhancement of deposition of low viscosity oils when they are incorporated into the subject invention.
In co-pending U.S. patent application Ser. No. 09/859,862 to Aronson et al. (entitled “Wet-Skin Treatment Composition”), filed May 17, 2001 and 09/859,849 to Aronson et al. (entitled “Method of Enhanced Moisture or Reduced Drying Using Wet-Skin Treatment Compositions”), there is disclosed benefit agents which provide a draggy feel. There is no teaching or disclosure however, of using benefit agent structurant with crystalline materials of specific aspect ratio or of how to produce such.
There is also some bar art relating to mixing benefit agents and carriers for use in soap base. U.S. Pat. No. 6,242,398 to Chambers et al., for example, discloses soap bar prepared by premixing benefit agents such as oils and humectants with solid carriers such as starches, followed by mixing with soap bar.
No prior art of which applicants are aware demonstrates the use of hydrogenated oils, fats, fatty acids or fatty alcohols having specific aspect ratio of crystals and prepared as a premix to enhance the deposition of benefit agents (e.g., skin nutrients such as, for example, sunflower seed oil).
Additionally, there is no prior art of which applicants are aware that demonstrates the use of these materials for structuring hydrophobic benefit agents so as to improve the properties (e.g., hardness, wear rate, mush) of personal product bars containing such benefit agents.